Non-involute Gears Research Articles

非インボリュート歯車用ピニオンカッタの設計製作法の研究 : 第3報,ピニオンカッタの研ぎ直しによる刃形誤差の解析(S44-5 設計I,S44 伝動装置の基礎と応用)

非インボリュート歯車用ピニオンカッタの設計製作法の研究 : 第3報,ピニオンカッタの研ぎ直しによる刃形誤差の解析(S44-5 設計I,S44 伝動装置の基礎と応用)

904 特殊歯形はすば歯車の振動特性と歯面強度(機素・潤滑II)

904 特殊歯形はすば歯車の振動特性と歯面強度(機素・潤滑II)

917 特殊歯形はすば歯車の歯面強度(機素潤滑設計II)

917 特殊歯形はすば歯車の歯面強度(機素潤滑設計II)

The Minimum Film Thickness in Line Contacts During Reversal of Entrainment

In contacts, such as cams, non-involute gears and shaft seals, where the direction of entrainment reverses during the operating cycle, the minimum film thickness is typically found just after the reversal. This paper shows that this minimum film thickness is determined by the rate of change of the entraining velocity and by the fluid and surface properties. For line contacts, four regimes of lubrication are found—as for the steady-state situation—and expressions for the film thickness in each regime are developed. This enables an outline design chart for the minimum film thickness to be constructed. It is shown that this information, together with the steady-state predictions is sufficient to determine the variation of film thickness with time in most situations where load, radius of curvature, and entraining velocity vary.

特集 性能向上のための歯車の役割 特殊歯形歯車の用途と課題

特集 性能向上のための歯車の役割 特殊歯形歯車の用途と課題

The Synthesis of Tooth Profile Shapes and Spur Gears of High Load Capacity

In this work a method is presented for the synthesis of high capacity noninvolute spur gears and tooth profiles. Two gear capacity criteria are used in the synthesis: (1) the capacity based on maximum allowable Hertz stress and (2) the capacity based on the bending strength of the tooth. These capacity criteria are related to a generalized noninvolute gear geometry which includes the factors number of teeth and contact ratio. It was found that there are certain optimal relationships which exist among the noninvolute parameters which lead to a solution, for a maximum capacity noninvolute gear pair. For a speed ratio of one to five it was found that a significant capacity advantage exists for the synthesized noninvolute gear pair (compared to a 20-deg involute spur gear pair) for moderate as well as high hardness values. For a speed ratio of one to one a capacity advantage was found for moderate hardness but the advantage decreased significantly for high hardness.